By Andreas Topp on Wednesday, November 24, 1999 - 04:56 am:
I`ve got a little problem. I have to investigate a mixture of 20 AA by RPHPLC-MS (microbore HPLC-ESI). The problem is that I can`t use derivatisation reactions like OPA etc. So I tryed to use a Ionic Pair reagenz (Heptafluoric butyricacid) for the AA. The problem is that at least 7 AA (Gly,Ala,Cys,Aspriginicacid, Glutaminicacid, Aspirigin, Glutamin) have nearly no retention. No I am searching for another method without Ionicpair Reagent. Who can help me?
with kind reguards
Andreas Topp
By alex on Wednesday, November 24, 1999 - 10:23 am:
This is probably a naive question, but I thought one of the advantages to LC-MS was that the MS could sort things out even if there was no separation (or retention, in this case)?